Abstract： Trivalent europium doped zinc oxide （ZnO：Eu3＋） nanocrystals were synthesized via room temperature chemical co-pre- cipitation and they were systematically characterized by means of X-ray diffraction （...Abstract： Trivalent europium doped zinc oxide （ZnO：Eu3＋） nanocrystals were synthesized via room temperature chemical co-pre- cipitation and they were systematically characterized by means of X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） and photoluminescence （PL） spectroscopy. The as-synthesized samples were found to have hexagonal wurtzite coexisted with the intermediate Zn5（OH）sC12·H2O phase, while the single hexagonal phase was facilitated due to the calcinations. The as obtained samples were broadly composed ofnanoflakes while the highly crystalline nanorods were formed due to low temperature annealing of the as-synthesized samples. The crystallite size of the nanoflakes and nanorods （40-90 nm） were extracted from the XRD pattern which was found to be consistent with scanning electron microscopy （SEM） measurements. The photoluminescence （PL） spectra of nanophosphors showed bright red and orange emissions at 618 and 594 nm respectively with efficient broad blue green emis- sion spectrum due to ZnO lattice. Further, a good energy transfer process from ZnO host to Eu3＋ was observed in PL emission and excitation spectra of Eu3＋ doped ZnO ions. In all, the present nanophosphors were found to have great potentiality for bio-appli- cations.展开更多
ZnO1-xTex ternary alloys have great potential to work as a photovoltaic （PV） absorber in solar cells. ZnOl-xSx is also a ZnO based alloy that have uses in solar cells. In this paper we report the comparative study o...ZnO1-xTex ternary alloys have great potential to work as a photovoltaic （PV） absorber in solar cells. ZnOl-xSx is also a ZnO based alloy that have uses in solar cells. In this paper we report the comparative study of various parameters of ZnO 1-x Tex and ZnO 1-x Sx for selecting it to be a competent material for solar cell applica- tions. The parameters are mainly being calculated using the well-known VCA （virtual crystal approximation） and VBAC （Valence Band Anti-Crossing） model. It was certainly being analysed that the incorporation of Te atoms produces a high band gap lower than S atoms in the host ZnO material. The spin-orbit splitting energy value of ZnOl-xTex was found to be higher than that of ZnOl-xSx. Beside this, the strain effects are also higher in ZnO^-xTex than ZnOl-xSx. The remarkable notifying result which the paper is reporting is that at a higher per- centage of Te atoms in ZnOl-xTex, the spin-orbit splitting energy value rises above the band gap value, which signifies a very less intemal carrier recombination that decreases the leakage current and increases the efficiency of the solar cell. Moreover, it also covers a wide wavelength range compared to ZnO1-x Sx.展开更多
文摘Abstract： Trivalent europium doped zinc oxide （ZnO：Eu3＋） nanocrystals were synthesized via room temperature chemical co-pre- cipitation and they were systematically characterized by means of X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） and photoluminescence （PL） spectroscopy. The as-synthesized samples were found to have hexagonal wurtzite coexisted with the intermediate Zn5（OH）sC12·H2O phase, while the single hexagonal phase was facilitated due to the calcinations. The as obtained samples were broadly composed ofnanoflakes while the highly crystalline nanorods were formed due to low temperature annealing of the as-synthesized samples. The crystallite size of the nanoflakes and nanorods （40-90 nm） were extracted from the XRD pattern which was found to be consistent with scanning electron microscopy （SEM） measurements. The photoluminescence （PL） spectra of nanophosphors showed bright red and orange emissions at 618 and 594 nm respectively with efficient broad blue green emis- sion spectrum due to ZnO lattice. Further, a good energy transfer process from ZnO host to Eu3＋ was observed in PL emission and excitation spectra of Eu3＋ doped ZnO ions. In all, the present nanophosphors were found to have great potentiality for bio-appli- cations.
文摘ZnO1-xTex ternary alloys have great potential to work as a photovoltaic （PV） absorber in solar cells. ZnOl-xSx is also a ZnO based alloy that have uses in solar cells. In this paper we report the comparative study of various parameters of ZnO 1-x Tex and ZnO 1-x Sx for selecting it to be a competent material for solar cell applica- tions. The parameters are mainly being calculated using the well-known VCA （virtual crystal approximation） and VBAC （Valence Band Anti-Crossing） model. It was certainly being analysed that the incorporation of Te atoms produces a high band gap lower than S atoms in the host ZnO material. The spin-orbit splitting energy value of ZnOl-xTex was found to be higher than that of ZnOl-xSx. Beside this, the strain effects are also higher in ZnO^-xTex than ZnOl-xSx. The remarkable notifying result which the paper is reporting is that at a higher per- centage of Te atoms in ZnOl-xTex, the spin-orbit splitting energy value rises above the band gap value, which signifies a very less intemal carrier recombination that decreases the leakage current and increases the efficiency of the solar cell. Moreover, it also covers a wide wavelength range compared to ZnO1-x Sx.
